Flat graver heel sharpening troubles

I recently bought the single angle sharpening fixture from GRS and am experiencing some troubles with its accuracy I wonder if any member might have a solution to-it’s very frustrating. Sharpening flats for bright cutting is what I have the problems with. Long story short… I cannot get a straight heel (belly) on the gravers., it constantly goes off to the left in an unacceptable manner. I have tried compensating by adjusting the zero angle to the right slightly but that didn’t work. I tried setting the zero angle by laying the graver flat on my ceramic stone and letting the graver adjust itself to zero loose and then tightening the calibration fixture but that didn’t work either.


I know how to use the power hone and fixtures properly having taken a course at GRS with Dianne Scalese. I have trued up the bottom of my gravers first, even going so far as to true them again (as a test mind you) after grinding and polishing the face, the resulting final heel grind always goes awry. I use the ceramic lap stone for the final belly 20 degree angle and have also messed with a very light stroke with the 1200 wheel. But consistently I never am able to get a parallel heel grind. It confuses me that the bottom of the graver being trued up very well to the face would result in a bad heel angle- I wonder if “operator error†or Gremlins are at play? Since I bright cut the heel needs to be exact..


If any of my descriptions point out something I may be doing wrong please, please let me know, I’m hoping another member may have a solution (short of returning it and hoping it was messed up in the first place). I don’t believe I have ever dropped the fixture or the post to misalign them. Once again, the face and bottom of the graver are all ground true before the heel is ground and only when the heel is ground do I experience a misalignment. Thanks in advance for any help.
Paul

Paul: using Mike Cirelli's grind on the top of a flat or onglette graver, you can mount it squarely in a Dual Angle fixture for sharpening. I'm not familiar with the single angle fixture, but if it's the first model they made 30 years ago, I think you can still use Cirelli's top grind to create a grind that will clamp more accurately. Check the Tips Archive for his tutorial.

I'm not sure if this applies but my ceramic wheel is a larger diameter than the rest of the wheels, this causes me to have to change the position of my sharpening fixture, where it sits on the hone surface, in order to polish the heel. This may create your problem. possibly. imho
David

Possibly your fixture is not zero'ed with your cutter blank and hone. If you set the fixture at zero both roationally and angle, and touch it to the wheel, you will immediately see if the tool is grinding flat and true, OR it may be grinding on one side of the blank.

Another possibility is that your graver is not truly square to begin with, if you are using a square tool bit.

Tom

I have the #003-100 Standard Graver Sharpening Fixture and sharpen on stones and have the same problem Paul and i never have found a soulition .I minamized it then just learned to live with it
http://www.grstools.com/toolsharpen.html#standard Its the first sharpning fixture.

Steve

Paul, sorry for your problem.
Have you checked to make sure the top of your lap machine case is flat?
That can throw you off when you move the fixture to the side to lap the heel.
Check it with a straight edge.
I cured one with a piece of 1/8 inch alum. by attaching it to the top.
Just another place to check.
Best, John B.

Yes, check your turntable parallelism with the base. Check the distance from wheel to machine top with a depth gage in several places around the perimeter.

Make sure the machine top, where the fixture sits, is flat. La a straight edge across it. If you can see light under the straight edge, then the machine top is warped.

Thanks everybody for all your help. I've read through all the advice and will try everything listed. I did have some good success at making my problem better. I called GRS and talked to JB at tech spupport and he was very helpful, they really are a good comapny and stand behind their work100% problems or not! He suggested (before returning it) recalibrating the fixture by loosening the set screw (allen head type) on the knob end of the handle. I loosened that as well as the zero degree set rings. Then with a graver in place I put the top of the flat graver down on the cermaic lap to level it and then clamped it securely but carefully in place with a C clamp. Then I zero'd in the tightening rings and snugged up the set screw. That did help but not 100%.

So being of the "Get a bigger hammer" philosophy I decided to manhandle the whole device when sharpening. Now I keep a good pressure toward the left of the post when I sharpen everything to compensate for it being off to the right (bird's eye view wise) and place my finger like Santa's against his nose against the tip of the graver as I sharpen and heel it pushing it to the left. The results are at least much more satisfactory now, being off only a little bit as opposed to the lot-O bit before And when I radius the heel it goes smoothly all across parallel as opposed to before when it was well rounded only to the left so bascially I'm way ahead of where I was yesterday thanks to the group and keeping my patience in tact. I'd say an 80% improvement and I'll work on the other 20% with technique.

Thanks Sam for the tip about sharpening an angle at the top of the gravers to fit into the dual angle fixture, I will try that on and old graver and see what happens. The dual angle fixture is a much more technically superior fixture I like a lot, and if I can use that to sharpen my flats the best of both worlds will be at my fingertips.

Thanks again to everybody for your help, having others think outside the box for me works wonders-Yeee Haaa!
Paul

Paul,
I didn't see any mention of your positioning of the fixture in relation to the rotating abrasive disk. I have found that for certain angles, it is critical to have the contact point of the graver to the abrasive disk at the 6 o'clock position so that it travels straight across the graver.

Peter

Paul,
If you are using the fixture pictured in your last post , there are 2 important things to check.
1-is the small screw in the the base of the fixture extended to change the baseplate angle? This will change the face angle if the fixture is rotated 90 deg.
2- There are 2 magnetic strips attached to the bottom of the baseplate - make sure they are both present and smooth, since any difference between them will change the post angle when the base is rotated.
Just a shot in the dark, but it can't hurt to check.
good luck, Don
www.Bellknives.com